The 21-year-old capped an impressive all-round display by hitting the winner against Philadelphia Union in the 76th minute of the pre-season warm-up at Lincoln Financial Field.
The strike was Obertan's first in United's colours since joining from Bordeaux last year.
Ferguson said: "Goals always help players of course, and when they are forwards in particular. There is a goal in Gabby, there is no question of that.
"The best aspect of his goal was his run, the timing of his run and the timing of the pass and the weight of the pass. It made it a really good goal. He has taken it well."